1. Field of the Invention
The present invention relaters to a pressure cooker and more specifically to a pressure release valve assembly used in a pressure cooker.
2. Prior Art
A pressure cooker that utilizes high-temperature and high-pressure steam to cook food inside the pot has been well known and used widely. Unfortunately, there is an omnipresent risk of explosion caused by too much pressure inside the pot. This risk is very real because a pressure cooker prohibits the free circulation of air between the interior and the exterior of the pot and cooks food under high-pressure and high-temperature conditions. So as to prevent this risk, several different counter measures have been taken, including using sturdier materials to construct pots, utilizing a timer to control the length of heating time, installing a pressure gauge to monitor the atmospheric pressure inside, installing a pressure release valve, and/or installing a safety cap made of metal mesh casing.
A pressure release valve for a pressure cooker that uses a safety cap is first disclosed by the inventor of the present application in the U.S. Pat. No. 7,726,508 and in the U.S. Patent Application Publication No. 2010-0193521. The safety valve is a device that is physically attached to a pressure cooker, and its function is to release the pressure or pressurized steam in a pot when the atmospheric pressure within the pot exceeds a pre-set point. The safety valve is usually installed in the lid of a pressure cooker. The portion of the safety valve outside of the lid is shaped like a pipe having apertures through which the pressurized steam gets into the pipe. The portion of the safety valve inside of (or under) the lid is an extension of the interior pipe, and it has a spring-laden cylindrical valve plunger and an aperture for releasing the pressurized steam in its wall. A safety cap is attached to the lower end of the interior portion of the valve to prevent food particles from coming into the safety valve and thus to avoid the valve from being clogged by the food particles and to prevent explosion of the pressure cooker. The safety cap works well to prevent clogging of the safety valve and therefore to prevent explosion of pressure cookers, providing safety and secure use of pressure cookers. Nonetheless, users can remove the safety cap from the lid of a pressure cooker for the purpose of cleaning; as a result, a user could forget to put the safety cap back on the pressure release valve or fail to completely attach the safety cap back on the pressure release valve, leading to eventual undesired consequences.